for-direction

Disallow for loops whose counter moves away from its bound

A counter that moves away from its relational bound cannot make a true loop condition false.
Instead, you MUST reverse the counter update or comparison direction.

An unconditional loop expresses intentional nontermination directly.

- Category: correctness
- Level: error
- Fix: suggestion
- Scope: module

Reported

for (let index: int32 = 0; index < 10; index--) {}
Accepted

for (let index: int32 = 0; index < 10; index++) {}
Prior art

- ESLint · for-direction

language/linter/src/rules/correctness/fordirection.rs:10